Body-insertable device system and in-vivo observation method

Abstract

An object of the present invention is to actively control at least one of the position and direction of the imaging field in a subject and to observe a desired observed region in the subject certainly in a short period of time. A body-insertable device system according to the present invention includes a capsule endoscope 1 introduced into a subject and a permanent magnet 3 . An imaging unit of the capsule endoscope 1 for taking an image inside the subject is fixed in a casing. The capsule endoscope 1 includes a drive unit for changing at least one of the position and posture of the casing in the liquid 2 a which is also introduced in the subject 100 . The permanent magnet 3 controls the operation of the drive unit for changing at least one of the position and posture of the casing in the liquid 2 a.

What is claimed is: 
     
         1 . A magnetic field generator operating method comprising:
 a generating step of generating a magnetic field for moving a capsule endoscope, which is in liquid, in a desired direction; and   a first step of controlling a magnitude of the magnetic field, which is exerted on the capsule endoscope in a vertical direction substantially parallel to a direction of gravitational force, so as to bring a whole surface of the capsule endoscope into contact with the liquid.   
     
     
         2 . The magnetic field generator operating method according to  claim 1 , wherein the first step comprises determining whether the capsule endoscope is under a liquid surface based on position and posture information of the capsule endoscope and controlling the magnitude of the magnetic field exerted on the capsule endoscope based on a result of determination. 
     
     
         3 . The magnetic field generator operating method according to  claim 1 , further comprising:
 a second step of controlling a magnitude of the magnetic field, which is exerted on the capsule endoscope in a substantially horizontal direction, so as to move the capsule endoscope in the substantially horizontal direction while the whole surface of the capsule endoscope is in contact with the liquid.   
     
     
         4 . The magnetic field generator operating method according to  claim 3 , wherein the second step comprises controlling a magnetic field strength in the vertical direction to maintain the contact of the whole surface of the capsule endoscope with the liquid and moving a magnetic field generator in the substantially horizontal direction. 
     
     
         5 . The magnetic field generator operating method according to  claim 3 , wherein the second step comprises controlling a magnetic field generator such that sum of magnetic force, gravitational force, and buoyant force, which are exerted on the capsule endoscope in the vertical direction, is substantially zero. 
     
     
         6 . The magnetic field generator operating method according to  claim 3 ,
 wherein a specific gravity of the capsule endoscope is larger than a specific gravity of the liquid and a magnetic field generator comprises a magnet for moving that generates the magnetic field,   the first step comprises increasing a magnetic field strength of the magnet for moving to move the capsule in a direction opposite to the direction of gravitational force, and   the second step comprises moving the magnet for moving in the horizontal direction substantially perpendicular to the direction of gravitational force.   
     
     
         7 . The magnetic field generator operating method according to  claim 3 ,
 wherein a specific gravity of the capsule endoscope is smaller than a specific gravity of the liquid and a magnetic field generator comprises a magnet for moving that generates the magnetic field,   the first step comprises increasing a magnetic field strength of the magnet for moving to move the capsule in the direction of gravitational force, and   the second step comprises moving the magnet for moving in the horizontal direction substantially perpendicular to the direction of gravitational force.   
     
     
         8 . The magnetic field generator operating method according to  claim 3 ,
 wherein a specific gravity of the capsule endoscope is smaller than a specific gravity of the liquid and a magnetic field generator comprises a magnet for moving that generates the magnetic field,   the first step comprises reducing a magnetic field strength of the magnet for moving to move the capsule in a direction opposite to the direction of gravitational force, and   the second step comprises moving the magnet for moving in the horizontal direction substantially perpendicular to the direction of gravitational force.   
     
     
         9 . The magnetic field generator operating method according to  claim 6 , further comprising:
 a third step of reducing the magnetic field strength of the magnet for moving until sum of magnetic force, gravitational force, and buoyant force, which are exerted on the capsule endoscope, is directed in the direction of gravitational force.   
     
     
         10 . The magnetic field generator operating method according to  claim 7 , further comprising:
 a third step of reducing the magnetic field strength of the magnet for moving until sum of magnetic force, gravitational force, and buoyant force, which are exerted on the capsule endoscope, is directed in a direction opposite to the direction of gravitational force.   
     
     
         11 . The magnetic field generator operating method according to  claim 8 , further comprising:
 a third step of increasing the magnetic field strength of the magnet for moving until sum of magnetic force, gravitational force, and buoyant force, which are exerted on the capsule endoscope, is directed in the direction of gravitational force.   
     
     
         12 . The magnetic field generator operating method according to  claim 1 ,
 wherein a magnetic field generator comprises a magnet for moving that generates the magnetic field, and   the first step comprises changing a magnetic field strength by changing a distance between the magnet for moving and the capsule endoscope.   
     
     
         13 . The magnetic field generator operating method according to  claim 3 , wherein the second step comprises controlling magnetic fields generated by plural electrical magnets, respectively, by a magnetic field generator to change the magnetic field exerted on the capsule endoscope in the horizontal direction.